Invention content
It is an object of the present invention to provide the new technology sides of a kind of MEMS inertial sensor, humidity sensor integrating device
Case.
According to the first aspect of the invention, a kind of MEMS inertial sensor, humidity sensor integrating device are provided, including
Common substrate is equipped with the movable mass structure for inertial sensor, the movable mass knot in the common substrate
Structure includes the anchor point fixed on a common substrate and is suspended at the movable mass above common substrate by anchor point, in institute
It states and the first humidity sensor capacitance structure, the second humidity sensor capacitance structure is additionally provided in common substrate, wherein described first
Humidity sensor capacitance structure, the second humidity sensor capacitance structure respectively include setting at least a pair of the on a common substrate
One fixed polar plate, the second fixed polar plate, each pair of first fixed polar plate, the second fixed polar plate gap in be filled with wet sensitive
Material;Further include first movable mass structure, the first humidity sensor capacitance structure is sealed in the common substrate
Cover;The second humidity sensor capacitance structure is in communication with the outside.
Preferably, wherein, the first humidity sensor capacitance structure has phase with the second humidity sensor capacitance structure
Same initial capacitance value.
Preferably, the first humidity sensor capacitance structure has identical with the second humidity sensor capacitance structure
Structure.
Preferably, be additionally provided with the second lid the second humidity sensor capacitance structure being encapsulated in the common substrate
Body, wherein, it is provided with through hole in second cover.
Preferably, it is provided with insulating layer between the anchor point, the first fixed polar plate, the second fixed polar plate and common substrate.
Preferably, the anchor point, movable mass and the first fixed polar plate, the second fixed polar plate are in the common substrate
It is upper that there is identical height.
The present invention also provides a kind of manufacturing methods of above-mentioned integrating device, include the following steps:
A) depositing insulating layer, and being performed etching to the insulating layer on a common substrate, the movement for forming movable mass are empty
Between;
B) MEMS structure layer is bonded in the upper end of insulating layer;
C) MEMS structure layer is performed etching, forms at least a pair of first fixed polar plate, at least a pair of second fixed polar plate;
D) respectively the first fixed polar plate, the second fixed polar plate gap in fill humidity-sensitive material, form the first humidity and pass
Sensor capacitance structure, the second humidity sensor capacitance structure;
E) continue to etch MEMS structure layer, form the anchor point and movable mass of movable mass structure, and by first
Humidity sensor capacitance structure, the second humidity sensor capacitance structure, movable mass structure separate;
F) the first cover is bonded in MEMS structure layer, by movable mass structure, the first humidity sensor capacitance
Sealing structure is in the common substrate.
Preferably, first cover by metal bonding in MEMS structure layer.
Preferably, before the step c), the step of MEMS structure layer is thinned to predetermined thickness is further included.
Preferably, it in the step f), further includes and the second cover with through hole is bonded in MEMS structure layer,
The second humidity sensor capacitance structure to be encapsulated in the step in the common substrate.
In the integrating device of the present invention, the first humidity sensor capacitance structure is due to being sealed in the first cover and common substrate
In the closed containing cavity surrounded, make it insensitive to extraneous humidity variation, and the second humidity sensor capacitance structure is due to exposure
In the external world, it is made to change extraneous humidity sensitive.First humidity sensor capacitance structure and the second humidity sensor electricity as a result,
Hold structure and may be constructed a pair of of differential capacitance structure.Two humidity sensor capacitance structures can generate extraneous common mode interference
Basically identical response, in this way, can be filtered out at least partly using the output signal of the first humidity sensor capacitance structure
Common mode interference signal in second humidity sensor capacitance structure output signal, and then the second humidity sensor capacitance can be improved
The stability and resolution ratio of structure output signal.
The integrating device of the present invention, may be used identical MEMS device technique, by capacitive MEMS inertia device and wet
It is integrated simultaneously on a single chip to spend sensor, cost can be effectively reduced, while MEMS inertia devices can also be greatly reduced
Part and the occupied chip area of humidity sensor.
It was found by the inventors of the present invention that in the prior art, MEMS inertia devices and humidity sensor are mostly using difference
Technological process, so by two different chips the detection of inertial signal and moisture signal can only be realized respectively, this is not
But the cost of manufacture is increased, while also increases the usable floor area of chip.Therefore, the technical assignment to be realized of the present invention or
It is that person never expects the technical problem to be solved is that those skilled in the art or it is not expected that, therefore the present invention is a kind of
New technical solution.
By referring to the drawings to the detailed description of exemplary embodiment of the present invention, other feature of the invention and its
Advantage will become apparent.
Specific embodiment
Carry out the various exemplary embodiments of detailed description of the present invention now with reference to attached drawing.It should be noted that:Unless in addition have
Body illustrates that the unlimited system of component and the positioned opposite of step, numerical expression and the numerical value otherwise illustrated in these embodiments is originally
The range of invention.
It is illustrative to the description only actually of at least one exemplary embodiment below, is never used as to the present invention
And its application or any restrictions that use.
Technology, method and apparatus known to person of ordinary skill in the relevant may be not discussed in detail, but suitable
In the case of, the technology, method and apparatus should be considered as part of specification.
In shown here and discussion all examples, any occurrence should be construed as merely illustrative, without
It is as limitation.Therefore, other examples of exemplary embodiment can have different values.
It should be noted that:Similar label and letter represents similar terms in following attached drawing, therefore, once a certain Xiang Yi
It is defined in a attached drawing, then in subsequent attached drawing does not need to that it is further discussed.
Referring to figs. 1 to Fig. 6, the present invention provides a kind of MEMS inertial sensor, humidity sensor integrating device, including
Common substrate 1 is equipped with the movable mass structure 7 for inertial sensor, the movable mass in the common substrate 1
Structure 7 include the anchor point 71 that is fixed in common substrate 1 and by anchor point 71 be suspended at 1 top of common substrate can kinoplaszm
Gauge block 70.Movable mass structure 7 is the important component of inertial sensor, is connected on anchor point 71 by elastic torsion-beam, and
Movable mass 70 is made to be suspended at the top of common substrate 1, is equipped between movable mass 70 and common substrate 1 and supplies movable quality
The space 8 that block 70 moves.When by the inertia force of respective direction, movable mass 70 can occur to move accordingly, so as to logical
The capacitance structure of composition is crossed to characterize the inertia force suffered by movable mass 70.In the present invention, inertial sensor can be top
Spiral shell instrument, accelerometer etc., specific structure, operation principle belong to the common knowledge of those skilled in the art, no longer have herein
Body explanation.
The first humidity sensor capacitance structure 5, the second humidity sensor capacitance structure are additionally provided in the common substrate 1
6, wherein, the first humidity sensor capacitance structure 5 includes being fixed at least a pair of first fixed polar plate in common substrate 1
50, there is between two the first fixed polar plates 50 gap 50a, humidity-sensitive material 51 is filled in the gap 50a.Humidity sensor
Structure, the operation principle of device belong to the common knowledge of those skilled in the art, wherein, humidity-sensitive material 51 can be nanofiber
Body can be obtained by plasma bombardment polymer material, and plasma can be oxygen plasma, argon plasma, gather
It can be polyimides, positive photoresist, negative photoresist, dimethyl silicone polymer, Parylene or other micro- electricity to close object material
The sub- common polymer material of technique.When humidity sensor works, humidity-sensitive material 51 can adsorb the hydrone in air so that
Dielectric constant between two the first fixed polar plates 50 changes, the capacitance for thus being formed two the first fixed polar plates 50
Value change, realize the measurement of air humidity.
Wherein, in order to improve the precision of output signal, multipair first fixed polar plate 50 can be set, to form multiple detections
Capacitance structure, multiple detection capacitance structure may be constructed the differential capacitance structure of the first humidity sensor.
Based on identical reason, the second humidity sensor capacitance structure 6 includes being fixed in common substrate 1 at least
A pair of second fixed polar plate 60 has gap 60a between two the second fixed polar plates 60, filled with wet in the gap 60a
Quick material 61.
The integrating device of the present invention, further includes the first cover 3 being encapsulated in common substrate 1, to form closed cavity volume
10, wherein, the movable mass structure 7, the first humidity sensor capacitance structure 5 are located in the cavity volume 10, that is to say, that
The movable mass structure 7, the first humidity sensor capacitance structure 5 are sealed in common substrate 1 by the first cover 3,
So that the first humidity sensor capacitance structure 5 is isolated from the outside and comes, that is to say, that the first humidity sensor capacitance structure
5 will not export corresponding capacitance with the variation of ambient humidity.And the second humidity sensor capacitance structure 6 then directly exposure
In the external world so that the second humidity sensor capacitance structure 6 can export corresponding capacitance with the variation of ambient humidity, with
Realize the detection to ambient humidity.
In the integrating device of the present invention, the first humidity sensor capacitance structure 5 is due to being sealed in the first cover 3 with sharing lining
In the closed containing cavity 10 that bottom 1 surrounds, make it insensitive to extraneous humidity variation, and the second humidity sensor capacitance structure 6 by
In being exposed to the external world, it is made to change extraneous humidity sensitive.First humidity sensor capacitance structure 5 and the second humidity as a result,
Sensor capacitance structure 6 may be constructed a pair of of differential capacitance structure.The extraneous common mode of 5,6 pairs of two humidity sensor capacitance structures
Interference can generate basically identical response, in this way, the output signal using the first humidity sensor capacitance structure 5 can be down to
The common mode interference signal in 6 output signal of the second humidity sensor capacitance structure is partially filtered out, and then second can be improved
The stability and resolution ratio of 6 output signal of humidity sensor capacitance structure.
In another embodiment of the present invention, it is additionally provided in the common substrate 1 by the second humidity sensor capacitive junctions
Structure 6 is encapsulated in the second cover 9 in common substrate 1, with reference to figure 7, wherein, through hole 90 is provided in second cover 9, is made
It obtains the second humidity sensor capacitance structure 6 to be in communication with the outside, to be detected extraneous humidity.Using the second cover
9, the influence that particle and other pollutants are fixed in external environment to the second humidity sensor capacitance structure 6 can be effectively reduced,
Meanwhile second cover 9 certain shielding action can also be played to extraneous electromagnetic interference, make the second humidity sensor capacitive junctions
The output of structure 6 is more stablized, signal-to-noise ratio higher.
In a specific embodiment of the invention, preferably described first humidity sensor capacitance structure 5 and second wet
Spending sensor capacitance structure 6 has identical initial capacitance value.In order to ensure that the first humidity sensor capacitance structure 5 and second is wet
It is basically identical to the response of extraneous common mode interference to spend sensor capacitance structure 6, farthest to filter out the second humidity sensor
It is wet to second to eliminate 5 output signal of the first humidity sensor capacitance structure for common mode interference signal in 6 output signal of capacitance structure
Spend the influence of the useful signal in 6 output signal of sensor capacitance structure, the first humidity sensor capacitance structure 5 and second wet
Spending sensor capacitance structure 6 has identical structure, makes the first humidity sensor capacitance structure 5 and the second humidity sensor capacitance
Both structure 6 has an essentially identical initial capacitance value, which the includes material of corresponding part, shape, size and
Forming position etc..
The integrating device of the present invention, anchor point 71, movable mass 70, the first fixed polar plate 50, the second fixed polar plate 60 can
To use single crystal silicon material, this allows for produce on the same MEMS structure layer a being made of single crystal silicon material above-mentioned
Structure.Wherein, convenient for technique, anchor point 71, movable mass 70, the first fixed polar plate 50, the second fixed polar plate 60 exist
There is identical height in common substrate 1.It may further be preferable that in order to ensure to insulate, anchor point 71, the first fixed polar plate 50,
Insulating layer 2 is provided between second fixed polar plate 60 and common substrate 1.
The present invention also provides a kind of manufacturing methods of integrating device, include the following steps:
A) layer insulating 2 is deposited in common substrate 1, and the insulating layer 2 is performed etching, forms movable mass
Space 8, with reference to figure 2;Wherein, earth silicon material may be used in insulating layer 2.
B) MEMS structure layer a is bonded in the upper end on insulating layer 2, with reference to figure 3;Wherein, MEMS structure layer a can be single
Crystal silicon material can be bonded in by mode well-known to those skilled in the art on insulating layer 2.
C) MEMS structure layer a is performed etching, forms the first humidity sensor capacitance structure 5, the second humidity sensor electricity
Hold the fixed polar plate of structure 6;Specifically, it with reference to figure 4, is performed etching in the corresponding position of MEMS structure layer a, to form at least one
To the first fixed polar plate 50, at least a pair of second fixed polar plate 60, between each pair of first fixed polar plate 50, the second fixed polar plate 60
It is respectively equipped with gap 50a, 60a.
These, it is preferred to before this step, further include the step of MEMS structure layer a is thinned to predetermined thickness.
That is in step b), thicker MEMS structure layer a is selected to be bonded on insulating layer 2, it is suitable to be thinned to again later
Thickness.In this way, it can prevent from damaging MEMS structure layer a in bonding process.
D) humidity-sensitive material 51,61 is filled in gap 50a, 60a, to form the first humidity sensor capacitance structure 5, the
Two humidity sensor capacitance structures 6, with reference to figure 5.
E) continue to etch MEMS structure layer a, form the anchor point 71 of movable mass structure 7 and movable mass 70, and
First humidity sensor capacitance structure 5, the second humidity sensor capacitance structure 6, movable mass structure 7 are separated, referred to
Fig. 6;
F) the first cover 3 is bonded on MEMS structure layer a, by movable mass structure 7, the first humidity sensor electricity
Hold structure 5 to be sealed in the common substrate 1, form integrating device as shown in Figure 1.
In a preferred embodiment is invented, metal 4 is additionally provided with, first cover 3 is bonded in by metal 4
On MEMS structure layer a.It may further be preferable that in above-mentioned steps f), further include 9 key of the second cover with through hole 90
It closes on MEMS structure layer a, the second humidity sensor capacitance structure 6 is encapsulated in the step in the common substrate 1.
The integrating device of the present invention, may be used identical MEMS device technique, by capacitive MEMS inertia device and wet
It is integrated simultaneously on a single chip to spend sensor, cost can be effectively reduced, while MEMS inertia devices can also be greatly reduced
Part and the occupied chip area of humidity sensor.
Although some specific embodiments of the present invention are described in detail by example, the skill of this field
Art personnel it should be understood that example above merely to illustrating, the range being not intended to be limiting of the invention.The skill of this field
Art personnel are it should be understood that can without departing from the scope and spirit of the present invention modify to above example.This hair
Bright range is defined by the following claims.